1 /* 2 * S390 version 3 * 4 * Derived from "include/asm-i386/mmu_context.h" 5 */ 6 7 #ifndef __S390_MMU_CONTEXT_H 8 #define __S390_MMU_CONTEXT_H 9 10 #include <asm/pgalloc.h> 11 #include <asm/uaccess.h> 12 #include <asm/tlbflush.h> 13 #include <asm/ctl_reg.h> 14 15 static inline int init_new_context(struct task_struct *tsk, 16 struct mm_struct *mm) 17 { 18 spin_lock_init(&mm->context.pgtable_lock); 19 INIT_LIST_HEAD(&mm->context.pgtable_list); 20 spin_lock_init(&mm->context.gmap_lock); 21 INIT_LIST_HEAD(&mm->context.gmap_list); 22 cpumask_clear(&mm->context.cpu_attach_mask); 23 atomic_set(&mm->context.flush_count, 0); 24 mm->context.gmap_asce = 0; 25 mm->context.flush_mm = 0; 26 #ifdef CONFIG_PGSTE 27 mm->context.alloc_pgste = page_table_allocate_pgste; 28 mm->context.has_pgste = 0; 29 mm->context.use_skey = 0; 30 #endif 31 switch (mm->context.asce_limit) { 32 case 1UL << 42: 33 /* 34 * forked 3-level task, fall through to set new asce with new 35 * mm->pgd 36 */ 37 case 0: 38 /* context created by exec, set asce limit to 4TB */ 39 mm->context.asce_limit = STACK_TOP_MAX; 40 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | 41 _ASCE_USER_BITS | _ASCE_TYPE_REGION3; 42 break; 43 case 1UL << 53: 44 /* forked 4-level task, set new asce with new mm->pgd */ 45 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | 46 _ASCE_USER_BITS | _ASCE_TYPE_REGION2; 47 break; 48 case 1UL << 31: 49 /* forked 2-level compat task, set new asce with new mm->pgd */ 50 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | 51 _ASCE_USER_BITS | _ASCE_TYPE_SEGMENT; 52 /* pgd_alloc() did not increase mm->nr_pmds */ 53 mm_inc_nr_pmds(mm); 54 } 55 crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm)); 56 return 0; 57 } 58 59 #define destroy_context(mm) do { } while (0) 60 61 static inline void set_user_asce(struct mm_struct *mm) 62 { 63 S390_lowcore.user_asce = mm->context.asce; 64 if (current->thread.mm_segment.ar4) 65 __ctl_load(S390_lowcore.user_asce, 7, 7); 66 set_cpu_flag(CIF_ASCE); 67 } 68 69 static inline void clear_user_asce(void) 70 { 71 S390_lowcore.user_asce = S390_lowcore.kernel_asce; 72 73 __ctl_load(S390_lowcore.user_asce, 1, 1); 74 __ctl_load(S390_lowcore.user_asce, 7, 7); 75 } 76 77 static inline void load_kernel_asce(void) 78 { 79 unsigned long asce; 80 81 __ctl_store(asce, 1, 1); 82 if (asce != S390_lowcore.kernel_asce) 83 __ctl_load(S390_lowcore.kernel_asce, 1, 1); 84 set_cpu_flag(CIF_ASCE); 85 } 86 87 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, 88 struct task_struct *tsk) 89 { 90 int cpu = smp_processor_id(); 91 92 S390_lowcore.user_asce = next->context.asce; 93 if (prev == next) 94 return; 95 cpumask_set_cpu(cpu, &next->context.cpu_attach_mask); 96 cpumask_set_cpu(cpu, mm_cpumask(next)); 97 /* Clear old ASCE by loading the kernel ASCE. */ 98 __ctl_load(S390_lowcore.kernel_asce, 1, 1); 99 __ctl_load(S390_lowcore.kernel_asce, 7, 7); 100 cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask); 101 } 102 103 #define finish_arch_post_lock_switch finish_arch_post_lock_switch 104 static inline void finish_arch_post_lock_switch(void) 105 { 106 struct task_struct *tsk = current; 107 struct mm_struct *mm = tsk->mm; 108 109 load_kernel_asce(); 110 if (mm) { 111 preempt_disable(); 112 while (atomic_read(&mm->context.flush_count)) 113 cpu_relax(); 114 115 if (mm->context.flush_mm) 116 __tlb_flush_mm(mm); 117 preempt_enable(); 118 } 119 set_fs(current->thread.mm_segment); 120 } 121 122 #define enter_lazy_tlb(mm,tsk) do { } while (0) 123 #define deactivate_mm(tsk,mm) do { } while (0) 124 125 static inline void activate_mm(struct mm_struct *prev, 126 struct mm_struct *next) 127 { 128 switch_mm(prev, next, current); 129 set_user_asce(next); 130 } 131 132 static inline void arch_dup_mmap(struct mm_struct *oldmm, 133 struct mm_struct *mm) 134 { 135 } 136 137 static inline void arch_exit_mmap(struct mm_struct *mm) 138 { 139 } 140 141 static inline void arch_unmap(struct mm_struct *mm, 142 struct vm_area_struct *vma, 143 unsigned long start, unsigned long end) 144 { 145 } 146 147 static inline void arch_bprm_mm_init(struct mm_struct *mm, 148 struct vm_area_struct *vma) 149 { 150 } 151 152 static inline bool arch_vma_access_permitted(struct vm_area_struct *vma, 153 bool write, bool execute, bool foreign) 154 { 155 /* by default, allow everything */ 156 return true; 157 } 158 159 static inline bool arch_pte_access_permitted(pte_t pte, bool write) 160 { 161 /* by default, allow everything */ 162 return true; 163 } 164 #endif /* __S390_MMU_CONTEXT_H */ 165